Elimination of tooth decay and/or periodontal disease caused by bacteria is important to dental hygiene. After a toothbrush has been used, a large number of bacteria cling to the bristles and onto the body of the toothbrush, even after the brush has been rinsed. Additionally, bacteria and fungi from other environmental sources within the bathroom can contaminate the toothbrush. These bacteria and fungi can grow and multiply on toothbrush bristles, handles, and the interface between the two while the toothbrush is being stored between uses. The bristles and the interface can be difficult to clean and over time significant levels of microbial contamination can build in this area.
Various means have been proposed for minimizing microbial contamination of toothbrushes. A self-sterilizing toothbrush is described in White et al., U.S. Pat. No. 2,216,333, and includes a combination of a water soluble salt (e.g., sodium carbonate) with an anti-microbial agent (e.g., sulfur). The two are fused to a solid hard body and attached to the head of the toothbrush at the base of the bristles. When exposed to water, the sodium carbonate dissolves, forming an alkaline solution that in turn dissolves some sulfur, which kills bacteria. Kent, U.S. Pat. No. 5,061,106, describes including capsules or microspheres in the tuft holes in which the bristles of a toothbrush are mounted. The capsules include a disinfectant or medicant that is released during use. Tseng et al., U.S. Pat. No. 5,340,581, describes a sustained-release matrix for dental application. The matrix includes an anti-microbial agent that is released over time when the matrix is exposed to water. The matrix may also include a colorant and a water-leachable substance to cause the matrix to change color corresponding with the depletion of the agent in the matrix.
Although several antimicrobial agents exist, the majority are not appropriate for contact with the delicate mucosal tissues of the mouth on a repeated basis. Furthermore, topical treatments of the fiber on plastic handles or bristles are not durable and are removed through the abrasive process of toothbrushing. What is needed is an antimicrobial agent which can be incorporated into the body, head or handle of the brush at the time of manufacture, which is free from toxic effect and is durable over the lifespan of the brush.